Gasoline compositions containing mixtures of phosphates of amino alkylene amides



, 3,150,941 GASOLINE ,CQMPGSETEQNS C(fiNTAlNING MEX- TURES; 61F PHG-SPHATES OF AMINO ALKYL- ENE AMTDES George J. Kautslry, El Cerrito, Eddie G. Lindstrom, Martinez, and lviaurice R. Barusch, Richmond, Calih, assignors to California Research Corporation, San Francisco, Calif, a corporation of Delaware No Drawing. Filed Feb. 16, 1961, Ser. No. 89,649 2 Claims. (Cl. 44-63) This invention relates to improved hydrocarbon fuel compositions suitable for operation in spark-ignition internal combustion engines, and particularly to gasoline compositions containing unique addition agents which function to reduce deposits in the induction system of spark-ignition engines. More particularly it relates to gasoline compositions containing such addition agents which have a minimum tendency to cause undesirable emulsification of moisture in gasoline.

In certain types of automative engine service, rough idling and engine stalling has long been a consistent problem and has required frequent carburetor adjustments and reconditioning in order to maintain satisfactory operation. This problem of poor idling has been accentuated and expanded with the increased traffic density in metropolitan areas and the use of multi-throat carburetors in private automobiles. It has been determined that a primary factor in poor idling operation is an accumulation of deposits in the throttle body section of the carburetor which causes an over-rich mixture at idle and a reduction in idle speed. The accumulation of deposits in the induction system of the engine, and, especially, in the throttle section of the carburetor is particularly pronounced in services requiring considerable idling, such as taxicab and door-to-door delivery service. In private automobile operation, this problem is particularly emphasized in the metropolitan areas where heavy city traffic is encountered with appreciable stop-and-go driving.

The critical accumulation point for these deposits is adjacent to the throttle plate, whose position controls the air fuel-ratio. As these deposits accumulate, the air flow at idle is restricted with no change in fuel flow, and a rich mixture results causing erratic idling and engine stalling. In order to compensate for the presence of these deposits, the throttle must be opened slightly by increasing the idle speed adjustment which, although allowing more air flow, automatically supplies more fuel. This requires a fuel correction by changing the idle mixture adjustment screw a compensating amount. The

amount of idle adjustment required to maintain satisfactory idle performance is an indication of the deposit build-up. Furthermore, deposits will often form in the idle air passageway causing restriction which allows the manifold vacuum to draw more gasoline into the engine, again causing rich idling and engine stalling.

It has been established that the primary source of these deposits is the contaminants in the intake air of the engine when operating at idle. The greatest source of these intake air contaminants is engine blowby, which accounts for approximately one-half of the deposits. Exhaust from other vehicles, dust, and other components classed as normal air pollutants contribute to the formation of deposits.

The hydrocarbon components of the gasoline fuel bear no direct relation to the formation of these deposits. Tests have indicated that unstable or aged gasolines having a high ASTM gum or high potential gum values produce no greater deposits than stable, low-gum gasolines under comparable operating conditions.

In contrast to the periodic mechanical adjustments and engine reconditioning necessary to compensate for the United States Patent presence of the carburetor and induction system deposits, it has now been found possible to provide a fuel corn position which is capable of preventing an accumulation or build-up of these deposits and will also function to" reduce the existing deposits. Thus, by operating a sparkignition engine with a fuel composition compounded in accordance with the present invention, it is possible to materially improve the idling operation of the engine and sustain this improved operation even under adverse conditions of intake air pollution.

In the patent application Serial No. 424,243, filed by Eddie G. Lindstrom and Maurice R. Barusch on April 19, 1954, and issued as US. Patent No. 2,839,372 on June 17, 1958, it has been shown and claimed that the incorporation in a hydrocarbon base fuel boiling Within the gasoline boiling range, of a small amount of an oil-soluble acyclic aminoallrylene amide, and preferably an acyclic aminoalkylene amide containing an aliphatic radical, such as an alkyl radical of less than 5 carbon atoms, and preferably of 2 to 4 carbon atoms, attached to the amino group, will provide a fuel composition which will effectively inhibit the build-up of deposits in the carburetor of an engine operated thereon. In addition, a gasoline composition containing this improving agent will substantially reduce and prevent the formation of deposits throughout the area of the air-fuel induction system of the engine.

A particular class of compound which functions as the above unique improving agents may be represented by the following general formula:

it in which R is an acyclic hydrocarbon radical containing 11 to 17 carbon atoms, A is an alkylene radical and preferably an 'alkylene radical containing 2 to 4 carbon atoms, and in the two occurrences of R one is hydrogen and the other is an aliphatic radical containing 4 and fewer carbon atoms, such as an alkyl, a hydroxyalkyl, or an aminoalkyl radical. It will be noted that the alternate positions of the aliphatic radical R in Formula I are representative of the isomeric forms of the compound, both of which are normally present to a greater or lesser extent, depending upon the reaction employed in the preparation of these compounds. These isomeric forms may be conveniently referred to as a linear amino amide with reference to the form:

R i-NHANHR n and as an amino tertiary amide with respect to the following form:

0 ANH2 RCN R (III) wherein the symbols R and A follow the definitions given for Formula I and R is an aliphatic radical containing 4 and fewer carbon atoms, such as an alkyl, a hydroxyalkyl, or an aminoalkyl radical.

The aforementioned improving agents may be prepared in accordance with conventional reactions involving the formation of amides. Thus, these compounds may be prepared by the condensation of a higher fatty acid, a salt or an ester thereof with N-aliphatic-substituted alkylene polyamines under conditions of reaction such as to control the condensation to the elimination of one mol of water. The higher fatty acid component of the reaction may be an acid such as lauric, myristic, palmitic, stearic, linoleic or oleic acid, while the polyamine reactant may be a polyalkylene polyamine or an N-(alkylene oxide) derivative of an alkylene diamine. In all instances, the alkylene group is preferably an ethylene, propylene or butylene group. This technique of preparing the amides is amply described in the examples of the aforementioned U.S. Patent No. 2,839,372. Other methods of preparing the amides may also be employed.

It is usually desirable to prepare or formulate these improving agents in the form of a concentrate to facilitate handling problems and permit a simple blending operation in the incorporation of the additive in the fuel. In the preparation of the concentrate, the improving agent is dissolved in a hydrocarbon solvent, and particularly an aromatic solvent, in a concentration range of at least 10 percent by weight, and-up to about 70 percent by weight.

By reason of their unique effectiveness, these oil-soluble acyclic amino-alkylene amides are incorporated in the hydrocarbon base fuel in relatively small amounts and, preferably within the range of about 0.0003 to 0.1 percent by weight. Although larger concentration may be employed, their effectiveness insofar as the reduction of carburetor deposit build-up is concerned, does not materially improve with additionalconcentration of the additive.

In a patent application Serial No. 717,572, filed by Eddie G. Lindstrom and Maurice R. Barusch on February 26, 1958-, and now abandoned, which was a continuation-in-part of the aforementioned application Serial No. 424,243, now US. Patent No. 2,839,372, it has been furthermore pointed out that salts of the aforedescribed amino amides with certain organic and inorganic acids may be .used to provide added improving characteristics to the agents and to the gasolinecompounded therewith. In particular, it was there pointed out that salts of the aminoalkylene amides with unsubstituted and substituted acids of phosphorus, such as phosphates, phosphonates and phosphites, are particularly attractive for this purpose, because of the known tendency of phosphorus to decrease surface-ignition in the combustion of gasoline in spark-ignition internal combustion engines. The amino amide salts of oxyphosphorus acids and of'phosphorus acids having-one or two organic radicals bound to the central phosphorus atoms, and of esters of these acids, particularly the phosphated amino amides derived from phosphoric acids (hydrates'of P and organo-substituted phosphoricracids, are eminently suitable as additives to gasoline for the purpose of reducing deposit-forming tendencies. The term amino. amide salts of organo-substitutedphosphoric acids, as employed in this description, is intended to include, in particular, salts of those phosphoric acids in which the organic substituent attached to the oxyphosphorus radical is a hydrocarbon radical, such as a phenyl, tolyl, cycloalkyl or alkyl radical. The amino amide salts of these organo-substituted phosphoric acids are found to be remarkably effective in reducing the carburetor deposits, especially the amino amide salts of alkyl phosphoric acids (monoalkyl dihydrogen phosphates) and dialkyl phosphoric acids (dialkyl hydrogen phosphates). For all practical purposes, the number of carbon atoms in an alkyl substituent of an alkyl-substituted phosphoric acid which is reacted with an amino alkylene amide'additive need not exceed 20, and preferably should be 16 and lower. As illustrative examples of operativephosphated amino amides there may be named: metaphosphates, pyrophosphates, monoethyl phosphates, diethyl phosphates, dicresyl phosphates, monoisoamylphosphates, di-n-nonyl phosphates and the like; Amino amide salts of ortho-, meta-, and pyrophosphoric acids and those of lower alkyl phosphoric acids (having from one to eightcarbon atoms per alkyl substituent) areparticularly suitable for use in gasoline. When the improving agents are employed in the form of their salts and particularly as a multi-functional agent, the incorporation of the additives in the gasoline may vary'over a wider range suchas, for example, from.

0.0003 to 1.5 percent by weight. Amounts in the range from 0.01 to 1.0 percent by weight are preferred in ordinary practical applications.

Commercial gasolines, after their production at the refinery, are blended with difierent additives to bring these gasolines to the desired quality, prior to being transferred to bulk storage tanks whence they are eventually distributed to the consumer market. Moisture is invariably present in the air, and a certain percentage of this moisture is breathed in into the blending tanks, or otherwise enters therein as by having become admixed with gasoline in one way or another prior to the blending operation, to be ultimately condensed as liquid in the blending tanks.

In the process of blending the aforementioned aminoalkylene amide additives with gasoline, using conventional mixing equipment and techniques, these aminoalkylene amides at higher concentrations, owing to the presence of moisture, tend to cause formation of emulsions which require an unduly long time to separate into two distinct phases: an upper bright gasoline phase, and a lower aqueous phase eventually settling at the bottom of the blending tank.

it is found that salts of the aforementioned aminoalkylene amides with phosphoric acids, namely, their salts with orthoand pyrophosphoric acids, and more particularly their salts with unsubstituted and/or alkylsubstituted orthoand pyrophosphoric acids eliminate, or at least significantly reduce, the occurrence of emulsions. The alkyl-substituted orthophosphoric acids (also designated in the art as acid monoand dialkyl esters of orthophosphoric acid, and alkyl monoand dihydrogen phosphates) suitable for the preparation of the amino amide salts efiiective as additives to gasoline for the purpose of eliminating formation of deposits without entailing the undesirable emulsification are monoaikyi phosphoric acids, dialkyl phosphoric acids, and mixtures there of, characterized by the presence of from 1' to about 3 alkyl carbon atoms in their molecular structure. Elfective aminoalkylene amide salt additives are derived from orthophosphoric acid esters containing from 4 to 8 alkyl carbon atoms in their molecular structure. The correspond ing amino amide salts of monoalkyl dihydrogen phosphates and dialkyl hydrogen phosphates of this kind, when present in'gasoline in small amounts from about 0.0003 to about 1.5% by weight, insteadof their corresponding free amino amides, are effective as depositeliminating detergent additives and also minimize formation of objectionable emulsions. Any emulsion which may form in the presence of moisture in a gasoline blending tank, rapidly breaks down, when these phosphatesare employed, with separation of water into the aqueous phase at the bottom of the tank. While operative amino amide salts of alkyl acid phosphates may be added to gasolines in amounts in the range from about 0.0003 to about 1.5 %-by weight, additions of about 0.0004 to about 0.04% by weight are generally preferred and found adequate for most practical purposes- The aforedescribed amino amide salts of alkyl phosphoric acids to be used as improved detergent-action additives to gasoline may be prepared in any conventional manner, for instance, by reacting a fatty acid amide of an alkylene diamine with a suitable alkyl phosphoric acid in a mol to mol ratio. Ratios lower than 1'11 may also be employed, if desired, in which case the final additive product will contain a greater proportion of phosphorus, and thus, when added to gasoline, will tend to contribute further to the minimization of surface-ignition in the engine. Ratios higher than 1:1 may also be employed, in which case the final additive product represents a combination of the amino amide alkyl phosphate salt and of the unreacted amino amide, both of these components contributing their detergent effects toward minimization of induction system and carburetor deposits.

The alkyl phosphate salts of amino amides are quite stable at ambient and moderately elevated temperatures, and thus they retain their effectiveness in gasoline while stored in the tanks. These salts are readily soluble in commercial gasolines down to temperatures as low as 20 F., when added to the gasoline in the proportions ranging from about 00003 to about 1.5% by weight and preferably from about 0.0004% to about 0.04% by weight.

Similarly to the unphosphated amino amides, these alkyl phosphoric acid salts, when added to gasoline, materially improve the operation of the engines, by decreasing the occurrence of stalling caused by ice formation on the carburetor under certain weather conditions, and provide a generally smoother engine operation and, consequently, better engine performance.

Furthermore, it has also been found that among the many phosphate salts of the amino alkylene amides, described hereinbcfore as suitable detergent-action additives to gasoline, particularly effective in minimizing emulsion formation in gasoline are mixtures of salts of a long chain hydrocarbon (N-alkyl or N-alkenyl) monocarboxylic acid amide of a particular polyamine, these salts having been produced by reacting such an amide with a mixture of an unsubstituted ortho-phosphoric and an alkyl-substituted phosphoric acid, the two acids in this mixture being employed for the reaction with the amide in a critical mol ratio to each other so as to produce a mixture of corresponding phosphate salts.

The particular preferred polyamine which is reacted with the long-chain hydrocarbon monocarboxylic acid to form the amide is diethylene triamine, although other like polyalltylene polyamines may be used, if so desired. The long hydrocarbon chain of the monocarboxylic acid employed in the reaction with the polyamine is an acyclic alkyl or alkenyl radical of 11 to 17 carbon atoms, those acids with hydrocarbon radicals of 1517 carbon atoms, for instance, with the C radical as in oleic acid, being particularly contemplated for the preparation of the amide. The amide is next reacted with a mixture of orthophosphoric acid and an alkyl phosphoric acid which may be either a monoalkyl phosphate ester, or a dialkyl phosphate ester and which has a total of from about 5 to about 20 alkyl carbon atoms.

Preferably, alkyl phosphates derived from primary aliphatic alcohols are to be used for the preparation of mixtures of salts of unsubstituted orthophosphoric acid and an alkyl phosphoric acid, in accordance with the present invention. Desirably, higher alkyl phosphates with a total of 4 or more alkyl carbon atoms will be combined with orthophosphoric acid in order to produce a mixture or" salts of the amide and to attain therewith the optimal detergency equivalent to that obtainable with corresponding unphosphated amides.

The reaction of the long-chain alkyl or alkenyl monocarboxylic acid with diethylene triamine is preferably carried out by using an excess of the poly-amine. This reaction is carried through the amide stage to the imidazoline product by elimination of 2 mols of water per 1 mol of the acid. After removal of excess polyamine, the desired amino amide is obtained by hydrolysis. This amide is then phospbated in a conventional manner.

The mol ratio of the orthophosphoric acid to the alkyl phosphoric acid in the mixture of acids to be reacted with the amide, may be varied from about 60:40 to about :60, the ratio of 50:50 (that is, an equimolar mixture) being preferred as that providing the optimum water tolerance properties and the desirable detergent action with respect to engine intake system deposits, comparable with the action of unphosphated acyclic amino alkylene amides described hereinabove.

T he preparation of mixed phosphoric acid salts of amino alkylene amides may be carried out in accordance with the procedures employed for the preparation of like phospl ate salts in the specification of US. patent application Serial No. 754,135, filed August 11, 1958, by Eddie G.

6 Lindstrom and Maurice R. Barusch, and issued as US. Patent No. 2,974,022 of March 7, 1961.

Instead of the amides, corresponding imidazolines may be produced by omitting the hydrolysis step in the preparation of the amide, and phosphates of these im'idazolines can then be prepared by reacting the imidazoline product with a mixture of orthophosphoric acid and an alkyl phosphoric acid in a mol ratio of from about 60:40 to 40:60 in accordance with the invention, preferably in the absence of Water and moisture which would tend to convert the imidazoline to the corresponding amide.

The resulting substituted (alkyl or alkenyl) imidazoline phosphates, obtained by reacting an imidazoline with onthophosphoric and an alkyl substituted phosphoric acid in a mol ratio of from about 40:60 to about 60:40, will provide adequate removal of deposits from the induction system or" an engine, and also will minimize emulsion formation in gasoline.

Although, as indicated hereinbefore, the phosphates of long-chain aliphatic monocarboxylic acid amides and, in particular, the phosphates 0f N-aliphatic-substituted aminoalhylene amides with a hydroxy-terminated aliphatic substituent (for instance, the monoisoamyl phosphoric acid salt of the oleic acid amide of N-(2-hydroxyethyl)- 1,2-ethylene diamine) are particularly effective in eliminating emulsion problems in gasoline, the detergency of these neutral phosphates is often found to be less effective in preventing deposit formation in the induction system of a spark-ignition engine.

On the other hand, because of the basic nature of those phosphates containing free amino groups in the mixture of orthophosphate and alkyl-phosphate salts of the diaminoalkylene amide (1:1 mol ratio), or of a corresponding substituted imidazoline, produced by reacting a longchain hydrocarbon monocarboxylic acid, such as oleic with diethylene triamine, the detergency of these mixed phosphates dissolved in gasoline in amounts from about 0.0003 to about 1.5% by weight is observed to be entirely adequate to effect the neutralization and the removal of the acid deposits in the air-fuel induction system of a sparkignition engine.

It was established in numerous comparison tests of individual phosphates and alkyl phosphates of the herein described polyaminoamides, that not one of them alone is capable of providing simultaneously an adequate detergency to dislodge and remove deposits from the induction system, an ample protective action against corrosion, and a sufficient capacity to prevent formation of and to cause collapse of the aqueous emulsions in the gasoline, Without occasional cloudiness or haze of this latter. Thus, although orthophosphates of the amino alkylene amides are effective in separating rapidly from the gasoline the aqueous phase which goes down to the bottom of the gasoline tank, their addition does not eliminate cloudy appearance of the gasoline, a factor which definitely prejudices its salability and prevents its conformance with the specification.

Addition of monoalkyl phosphates of the amino alkylene amides in general does not contribute to the appearance of haze in the gasoline; however, expulsion of the water from the gasoline to the bottom of the tank (phase separation) occurs very slowly, and While wateringasoline emulsion is being suppressed, gasoline-in-water emulsion is apt to occur and to persist.

Similarly, dialkyl phosphates of the afore-mentioned amides yield bright gasoline, but the process of phase separation is very, very slow, taking up hours before the gasoline re-aquires salable appearance.

Therefore, it was utterly surprising to find that mixtures of orthophosphatcs and alkyl phosphates of these amino alkylene amides in the mol ratios from about 60:40 to about 40:60 and, in particular, in the mol ratio of 50:50 (as an equimolar mixture), not only act as effective detergents for the elimination of the deposits from the induction system, but also provide the desired rapid separation and facilitate withdrawal of the aqueous phase from the gasoline in thetank.

' This discovery hasbeen confirmed in an extensive series oftests, namely: (1') amodification of the Glass Throttle- Body Test, and (2) modification of Water Tolerance Test (cf. Federal Test Method Standards No. 791, Method 3251, Interaction of Water and Aircraft Fuels.) I

The modification of the Glass Throttle-Body Test, previously described in the aforementioned U.S. Patent 2,839,372. and US. Patent No. 2,974,022, is here designated as the Glass Throttle-Body Deposit Removal Test. In this modification, a 6-cylinder Plymouth automobile engine is set up in the laboratory and is provided with a conventional carburetor, again modified as described in the above-mentioned US. patent by the introduction of a similar removable glass throttle-body section between the carburetor body and the original cast-iron throttle body. This glass throttle-body is a section of glass tubing /i" thick, of approximately 1% outside diameter and about 1%" long. An automatic cycler or timer, which consists of a constant-speed electric motor and a magnetic clutch, is provided for insuring cyclic operation of the engine with 7.5 min. idle periods followed by accelerations to 2,000 rpm. Crankcase fumes are vented to the carburetor air inlet, since these fumes ar now known to be responsible for the larger portion of t re deposits; The engine is started up, using leaded gasoline containing a conventional amount of tetraethyl lead (1.5 ml./ gal.) but no surface-active additives of any kind. It is run for one hour with the blowby fumes being drawn in at the air intake. The engine is then stopped, the glass body is removed, and both sides of it are photographed. Thereupon the dirty glass body is again installed on'the engine and run for four hours on the same leaded base gasoline compounded with the detergent-action phosphated amide additive. This time the blowby fumes are not piped to the carburetor. After the run is completed the glass throttle-body is again photographed, and the effectiveness of the phosphate-containing gasoline (the percentage of cleanup of deposits) is visually estimated. The percentages of cleanup obtained with leaded gasoline containing different representative mixed phosphatesof oleic acid amide of diethylene triamine are given hereinafter in Table I.

Table 1 Parts per million parts of gasoline Percent cleanup Additive 50:50mixturc of o-phosphate and monoisoamyl phjgsphate... 168 90 The results clearly indicate that mixed phosphates prepared and employed in accordance with the present invention, that is in the mol ratio of from about 40:60 to about 60:40, are effective detergents for removing carburetor deposits.

The modified Water Tolerance Test consists essentially in placing 80 ml. of gasoline containing the phosphate additive(s) and 20 ml. of distilled Water into a 100 ml. graduate. The container is stoppered and vigorously shaken by hand, whereupon it is set at rest on a flat surface, observing the time required for the separation of two bright phases (gasoline and water) without any noticeable formation of an emulsion at the interface.

The followin typicalequimolar mixtures of phosphates of oleic acid amide of diethylene triamine were tested,

5% when present in gasoline in a concentration of about 390 ppm. (parts per one million parts of the gasoline).

Orthophosphate and isoamyl o-phosphate Orthophosphate and isooctyl o-phosphate Orthophosphate and decyl o-phosphate Orthophosphate and lauryl o-phosphate Orthophosphate and oleyl o-phosphate Orthophosphate and diisoamyl o-phosphate Orthophosphate and diisooctyl o-phosphate Orthophosphate and diisoarnyl pyrophosphate in all instances, phase separation occurred in less than three minutes. The gasoline was bright, and the reduction of deposits was substantially equal to that obtainable with gasoline containing the corresponding unphosphated oleic acid amide.

A rigorous engine test of 156 hours duration was carried out, using leaded gasoline containing the afore- 'mentioned equirnolar combination of the orthophosphate tained at 2% i The engine was operated by means of an automatic cycling device or timer, varying the engine load at aspeed of l75-1800 r.p.m., with intermediate idle' periods and with shutdowns of 3 minutes each. The presence of the mixture of phosphates in the gasoline in accordance with the invention resulted in the reduction of the intake system deposits by about 40%. Surface-ignition was virtually eliminated.

In addition, utilization of the mixture of 'orthophosphate and alkyl phosphate of an amino alkylene amide, or of a corresponding substituted imidazoiine reduces the risk of corrosion of the engine. Unsubstituted orthophosphate is a rather poor corrosion inhibitor, whereas alkyl phosphates having 5 or more alkyl carbon atoms are good rust inhibitors, and in the mixture with unsubstituted orthophosphate the beneficial anti-corrosive action of the alkyl phosphate prevails.

As in the case of the amino amides, it is desirable to formulate and to supply the phosphate salts and, in particular, the preferred mxtures thereof in the form of concentrates, so as to facilitate handling and to permit a simple blending operation for incorporating the phosphate additives in the gasoline.

These concentrates suitable for shipping and handling are prepared by dissolving from about 10 to about 70% by weight of the corresponding phosphate additive material in an organic solvent boiling substantially in the gasoline range, preferably in a hydrocarbon solvent, and, particularly,.in an aromatic'hydrocarbon solvent boiling in the range from about 300 to about 400 F.

When the gasolines, which are to be improved by the addition of the preferred amino amide phosphates of the present invention, are intended for use in the areas of low winter temperatures, it may be desirable to replace a portion of the hydrocarbon'solvent in the concentrate of the phosphate by a compatible aliphatic alcohol, saturated aliphatic alcohols of 3 to 6 carbon atoms, such as isopropanol, methyl isobutyl carbinol, n-butanol, and the like, being suitable for the purpose.

In addition to the improving agents hereinbefore described, other conventional fuel additives may be incorporated in the fuel composition. An added factor in the reduction of deposits Within the air-fuel induction system of the engine may be obtained by the incorporation, in combination with the subject improving agents, of a nonvolatile oil, such as a light mineral lubricating oil or a petroleum spray oil, which functions as a carrier for the deposits dispersed by the amino amide improving agents. Satisfactory results have been obtained by incorporating a nonvolatile oil in the range of between 0.05 to 0.5 percent by volume and have shown effectiveness in the reduction of deposits in the area of the intake ports of the engine.

It is to be understood that many modifications and variations of the invention as described hereinbefore, may be made without departing from the spirit and scope thereof, and that only such limitations should be imposed thereon as are indicated in the following claims.

We claim:

1. An improved gasoline fuel, characterized by reduced tendencies towards engine deposit formation and corrosion, and comprising a major proportion of a hydrocarbon base fuel boiling in the gasoline boiling range and having incorporated therein from about 0.0003 to 1.5% by weight of a mixture of two salts, one of said salts hing a salt of an unsubstituted non-alkylated orthophosphoric acid and the amide reaction product of diethylene triamine and a long-chain C -C hydrocarbon monocarboxylic acid selected from the group consisting of Gig-C13 alkyl and C C alkenyl monocarboxylic acids, and the other salt being a salt of a C C alkyl hydrogen phosphate and the same aforesaid reaction product of diethylene triamine and a long-chain C -C hydrocarbon monocarboxylic acid, the mol ratio of said unsubstituted orthophosphoric acid salt to said salt of an alkyl hydrogen phosphate being in the range from about 40:60 to about 60:40, thereby assuring, in addition to the reduction of deposits and corrosion, a substantially complete disappearance of cloud and imparting brightness to said gasoline in less than 3 minutes after the addition thereto of said mixture of two phosphates.

2. An improved gasoline fuel, characterized by reduced tendencies towards engine deposit formation and corrosion, and comprising a major proportion of a hydrocarbon base fuel boiling in the gasoline boiling range and having incorporated therein from about 0.0003 to 15% by weight of a mixture of two salts, one of said salts being a salt of an unsubstituted non-alkylated orthophosphoric acid and the amide reaction product of diethylene triamine and oleic acid, and the other salt being a salt of diisoamyl hydrogen phosphate and the same aforesaid reaction product of diethylene triamine and oleic acid, the mol ratio of said orthophosphoric acid salt to said salt of diisoamyl hydrogen phosphate being in the range from about :60 to about :40, thereby assuring, in addition to the reduction of deposits and corrosion, a substantially complete disappearance of cloud and imparting brightness to said gasoline within less than 3 minutes after the addition thereto of said mixture of two phosphates.

References Cited in the file of this patent UNITED STATES PATENTS 2,014,924 Benedict Sept. 17, 1935 2,312,082 Dietrich Feb. 23, 1943 2,340,881 Kelley et al. Feb. 8, 1944 2,387,501 Dietrich Oct. 23, 1945 2,508,924 Mertens et a1. May 23, 1950 2,568,876 White et al Sept. 25, 1951 2,728,647 Vaughn Dec. 27, 1955 2,794,721 Bartleson June 4, 1957 

1. AN IMPROVED GASOLINE FUEL, CHARACTERIZED BY REDUCED TENDENCIES TOWARDS ENGINE DEPOSIT FORMATION AND CORROSION, AND COMPRISING A MAJOR PROPORTION OF A HYDROCARBON BASE FUEL BOILING IN THE GASOLINE BOILING RANGE, AND BY WEIGHT OF A MIXTURE OF TWO SALTS, ONE OF SAID SALTS BING A SALT OF AN UNSUBSTITUTED NON-ALKYLATED ORTHOPHOSPHORIC ACID AND THE AMIDE REACTION PRODUCT OF DIETHYLENE TRIAMINE AND A LONG-CHAIN C12-C18 HYDROCARBON MONOCARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF C12-C18 ALKYL AND C12-C18 ALKENYL MONOCARBOXYLIC ACIDS, AND THE OTHER SALT BEING A SALT OF A C5-C20 ALKYL HYDROGEN PHOSPHATE AND THE SAME AFORESAID REACTION PRODUCT OF DIETHYLENE TRIAMINE AND A LONG-CHAIN C12-C18 HYDROCARBON MONOCARBOXYLIC ACID SALT TO SAID SALT OF AN ALKYL HYDROGEN PHOSPHATE BEING IN THE RANGE FROM ABOUT 40:60 TO ABOUT 60:40, THEREBY ASSURING, IN ADDITION TO THE REDUCTION OF DEPOSITS AND CORROSION, A SUBSTANTIALLY COMPLETE DISAPPEARANCE OF CLOUD AND IMPARTING BRIGHTNESS TO SAID GASOLINE IN LESS THAN 3 MINUTES AFTER THE ADDITION THERETO OF SAID MIXTURE OF TWO PHOSPHATES. 